LOS ANGELES (AP) - Animation pioneer William Hanna, who with partner Joseph Barbera created such beloved cartoon characters as Fred Flintstone, Yogi Bear and Tom and Jerry, died Thursday. He was 90.

Hanna died at his North Hollywood home with Violet, his wife of 65 years, at his side, said Sarah Carragher, a spokeswoman for Warner Bros., which owns Hanna-Barbera Studios. She said he had been in declining health for the last few years.

Hanna and Barbera collaborated for more than a half-century, first teaming up when both worked at MGM in 1937. They created the highly successful Tom and Jerry cartoons, the antics of a cat and mouse team that won seven Academy Awards, more than any other series with the same characters.

They broke new ground by mixing Tom and Jerry with live action stars such as Gene Kelly in ``Anchors Aweigh'' and Esther Williams in ``Dangerous when Wet.''

They found new success in the 1950s with a witty series of television animated comedies, highlighted by ``The Flintstones,'' ``The Jetsons'' and ``Yogi Bear.'' ``Huckleberry Hound and Friends'' won the first Emmy Award given to an animated series.

Their strengths melded perfectly, critic Leonard Maltin wrote in his book ``Of Mice and Magic: A History of American Animated Cartoons.''

In a medium where the best work combined unforgettable characters and funny situations, Hanna brought cuteness, warmth and a keen sense of timing, while Barbera supplied the comic gags and skilled drawing.

``This writing-directing team may hold a record for producing consistently superior cartoons using the same characters year after year - without a break or change in routine,'' Maltin wrote.

Hanna was born in Melrose, N.M., on July 14, 1910. He left college to work as a construction engineer, but lost the job in the Depression. He found work with Leon Schlesinger, head of Pacific Art and Title, a cartoon production company.

In 1930, Hanna signed with Harmon-Ising Studios, the company that created the Looney Tunes and Merrie Melodies cartoon series, where he worked as a member of the story department, as a lyricist and a composer.

One month after being hired at MGM, he formed his partnership with Barbera.

Hanna said ``I was never a good artist,'' but he said Barbera ``has the ability to capture mood and expression in a quick sketch better than anyone I've ever known.''

The two first teamed cat and mouse in the short ``Puss Gets the Boot.''

When it was a hit with audiences and got an Oscar nomination, MGM let the pair keep experimenting with the cat and mouse theme, and the full-fledged Tom and Jerry characters - almost always telling the story entirely in action, not dialogue - were the result.

The team's move into television wasn't planned; they were forced to go into business for themselves after MGM folded its animation department in the 1950s.

With television's sharply lower budgets, their new animated stars put more stress on verbal wit rather than the highly detailed, and highly expensive, action of the theatrical cartoon.

Like ``The Simpsons'' three decades later, ``The Flintstones'' found success in prime-time TV by not limiting its reach to children. It ranked in the top 20 shows in the 1960-61 season and Fred Flintstone's ``yabba dabba doo'' soon entered the language.

The show's creators freely admitted it was a parody of ``The Honeymooners,'' with Fred Flintstone as Jackie Gleason and Barney Rubble as Art Carney. (Likewise, Yogi Bear was modeled on Phil Silvers' character of Sgt. Bilko in ``The Phil Silvers Show.'')

``You can read a lot into it,'' Hanna once said. ``You can compare Fred and Barney Rubble with Gleason and Carney.''

The Jetsons, which debuted in 1962, were the futuristic mirror image of the Flintstones.

``Somebody said, 'What's next?' and we went from the rock era into the future,'' Barbera said at a celebration when the show turned 25 in 1987. ``It wasn't that brilliant, really, but we used a lot of gimmicks and gadgets and it worked.''

Hanna-Barbera received eight Emmys, including the Governors Award of the Academy of Television Arts & Sciences presented in 1988.

AP-NY-03-22-01 2046ESTCopyright 2001 The Associated Press.

CORRECTION: In the obituary of cartoonist William Hanna, The Associated Press erroneously reported that the TV character Sgt. Bilko served as the model for Yogi Bear. Bilko was the model for Top Cat.